Method of forming enlarged ends on carbon filaments



l-that a current shall be passed onlythrough accompanying drawing, andto the letters of under high heat.

regulated.. -The vapor is allowed topass.

THOMAS EDISON,

or M13-snc more, 'New JERSEY. i

METHOD or nieuwe ENLARGED ENDS-fon crimson.` rt-LAMENT'S.,

srEcImcATroN farming pm of ,Letters raum ivo. '239;151, dated iApplication tiled Xovcnlbcr 24, '1860.

Io all4 whom it may concern:

Be it known. that I, THOMAS A. EDISoN, ot" Menlo lark, Vin the. countyot' Middlesex and State of New Jersey,have invented. a new and usefulMethod of Forming Enlarged Ends on I d o hereby declare that thefollowing is av t'ull'andexact description of the same, reference beinghad' to the reference marked thereon. Y

A's hitherto explained in `various applica` tions for patents by inetriade and now on tile, very desirable carbons for incandescent elec-.tric lamps may be made of various vegetable fibrousA Substances. As thebody or illuminating portion ot' suclr carbons is exceedingly smallamere tilament or thread-like body--it isnccessary that they be providedwith ends greatly enlarged, in order to aiTord a good electrical contactwith the clamps in which they are secured; \\`ith-Some materials, suchas paper, wood, bamboo, &c., it is possi-ble to makethesc enlarged endsintegral with and a lnn'tot'thecarbonitself, by suitably shapingthematerial priorto carbonization.V Other bers, however-such, for instance,.as monkeybast-are Simple filaments, and the enlarged ends have to bebui-lt upon them. In prior applications l have disclosed several methodsof acccn'lplishing this.

The object ot' this invention is to furnish another method and means formaking the necessary enlarged ends, and 'to that'end it consists in thefeatures more particular ly hereinafter described and claimed.`

ln carrying the invention into efi'ect, a'carbon is so attached to,electricalv conductors the portion or portions which it is desired toenlarge. It is thcn'plaetal in a glass globe or receiver having a smallopening in its top. Connected with thev globe'are means for genen' atingand passinLrf-into the. globe a stream of hydrocarbon vapor capable ofdecompt'rsition ln the electrical circuit'are placed resistant-es', b v1wh ich is regulated the pressure ofthe current passing through thecarbon. A shunt is 'arranged with a galvanomejter and resistances, sothat the amount of current. passing through the carbon may be '(Xomodel.)

through the globe until all the air therein. is` displaced, theexcess'ot vapor being burned at;V

thel opening in the top of the globe. The circuit being closed, theportions of the carbon thro'nglrwiiich it passes are heatedthereby toincandescencep tiguous thereto, withthe 'result that the carbontherefrom is portion of the conductor. AThe p rocessis kept up until theportions referred to are suiciently enlarged.' 4

In the drawing i-s' shown au arrangement of means well calculated tocarry into elfect the invention, although the invention is'not limitedto the employment-ot' the precise means therein illustrated. p

`H is the glass globe or holder, lmvingaper-v ture o in its-top, whilethe bottom thereof is sealed bythe stopple S, through which passes thesupport ofthe carbon C. The carbon C` is Secured in temporary clamps B aa', of which a isconnectedto qconductor 1. and a to decmnposin g thevapor con' deposited upon the heated" conductor il, ot'a circuit of anysuitable Source ot' electricity, while the clam p B connects both limbsofthe carbon, so that the circuit is rav I aB a L'. The distance betweenB, a, and ar is equal to the portion of' the carbon which it is desiredto enlarge. A

Y isa waterreservoir, in which is atank, T,

for containing a carbon compound Vcapable of vaporization under moderateheat. lFrom it apipe, p, leadsto and communicates with H.

l is a Vsteam-pipe havinga branclnp, leading into Y, andanother leadinginztothe jacket .l around p.' Steam .being admitted thereto heatsthe'water in Y, causingt'l'ievaporization ot' the compound in T, whilethe Steam in jacket .l heats pto a Vdegree prevent-ing eonashunt to vthecarbon, so that the amount; of current passi regulated.

The parts being in position, the vapor from T passes throughH, the'surplus burning-ato G is a galvanometer, and R an adjustable resistancein a derivedci'rcuit` to 1 forming ng thereto may be indicated and I and.preventing access of airto the interior; the circuit; is closedat K,whereupon the car bon between a and B and a.' audjf'is heated,

decomposing the vapor 'and ,causing n deposi tionrof carbon uponthehented portions. vThis deposition issinnlich-ioni',and uniform, andis allowed to proceed until the portion-s are su'lcient-ly built. up toall'ord `good clamping-snr- In's t ead of a separate tank for the'carbon l compound, a`small1eerxoir-nmy bemolle, di

re'ctly :rttnohed 4to ond oo mmnnicitingr with the globe"` orreceiver-H, and a place of solid i .lcfarbon compound', snclos solidnaphtlhag line, placed in- 4Such' Vslpnnll Yattachedreservoir,

Heat being: applied thereto, carbon vapor passes into the globe andoverall-d :xroundthe carbon nnder'treatlnent, with the 'as in thetberrconstrnctionl I ldo not claim herein, broadly, the depos'tonofcarbonbyeleclricalincandesceneefrom a carbon compound, as such waspracticedn early years by B'ut'vand Holi', and others; but

' gamin smile result" "-fWhac-I do claimi's-Q 'Y i .L Tbe method hereindescribed of forming sistng informing :in eieetrioal circuiti only 255.`enlarged ende upon carbon conductors. oohV throngh'the portion desiredto be enlarged,

thereby.; he'zitnghe same in a vessel-*through 'which ows a stream ofvapor from acarbon oom-pound, substantially as set-forth.

Q. The combination of a receiving' globe or ehmnber,n`1em1s for passingtherethrough a' s-rezini of. vapor f rom a carbon compound, and.

means-fiar formingnn eleetricalcrcnit through :my desired portion orportions of a carbon wnd'n'etor within s'aid globe or-chamber, sub#etmltial'ly :1 s`set forth.

19th da; of November, 1SSO. c Y

ERNEST J. BERGGREN.

This .Specilienl ion Signed 'and'witneseed this..

